The suffix of binary compounds depends on whether the compound is ionic or covalent.

Here's a breakdown:

Ionic Compounds:

* Metal-Nonmetal: The nonmetal element usually ends in -ide.

* Example: NaCl (Sodium Chloride)

Covalent Compounds:

* Nonmetal-Nonmetal: The last element in the formula usually ends in -ide.

* Example: CO₂ (Carbon Dioxide)

Important Note: While the suffix -ide is common for both ionic and covalent compounds, there are some exceptions and specific naming conventions for covalent compounds based on the number of each element present.

For instance, prefixes like "mono-", "di-", "tri-", "tetra-", etc., are used to indicate the number of atoms of each element in a covalent compound. These prefixes are used before the name of the element, except for the first element, where "mono-" is usually omitted.

Let me know if you'd like more examples or a deeper dive into the naming conventions for covalent compounds!